Many conventional photographic processors comprise a plurality of tanks containing various processing fluids, each tank having a plurality of rollers for transporting the light sensitive material therethrough. A web of light sensitive material in continuous or sheet form is transported through the tanks in a generally sinusoidal path. The web is continuously contacted by the rollers leading to possible scratching of the light sensitive material. Typically, the rollers are driven so that the surface speed of the rollers matches the speed of the light sensitive material. Any agitation of the fluid is the result of the relative motion between the fluid and light sensitive material.
A variety of photographic processors have been proposed which attempt to reduce the contact between light sensitive material and drive rollers to thereby reduce the possibility of scratching or marring of the material being processed. The proposed processors aim for uniform distribution of the processing fluid directed onto the light sensitive material to obtain uniform development of the material. Such processors also aim for increased chemical transfer rates to and from the light sensitive material being processed. They also attempt to contain the processing fluids within their respective tanks to prevent contamination of the processing fluids.
Conventional film or paper processes generally use external pumps to circulate processing fluids within the processor tanks to insure constant mixing of bulk solutions and in some cases to provide agitation of the solutions near the surface of the film. In most cases these pumps require external connections to the tank resulting in maintenance problems due to leakage at the connections. In addition a substantial amount of energy is expended in moving fluid through the restrictive plumbing system.
Some of the problems discussed above are alleviated by the processor designs disclosed in commonly assigned U.S. Pat. Nos. 4,994,840 and 4,989,028 to Hall et al; U.S. Pat. No. 5,136,323 to Frank et al; U.S. Pat. No. 5,172,153 to Lee F. Frank et al; and copending application Ser. No. 07/633,490 filed Dec. 28, 1990 by Lee F. Frank. Such patents and applications disclose processing apparatus which process a web while it is positioned in a plane or transported through a path without the use complicated roller transport apparatus. In U.S. Pat. Nos. 5,136,323 and 5,172,153 there are disclosed parallel plate processors which transport a web through a treatment channel having one or more fluid injection sites at which fluid is injected into the channel on opposite sides of the web. The channel has one or more evacuation sites spaced from the injection sites for evacuating fluid from the channel. The parameters of the system are selected such that the chemical boundary layer of the processing fluid has a thickness to maintain a chemical transfer rate in the fluid that exceeds the chemical transfer rate in the web. In U.S. application Ser. No. 07/633,490 there is disclosed a processor comprising a plurality of hydrostatic bearings for supporting and processing a web of light sensitive material. Processing fluid is supplied to the bearings by a pump in a separate chamber. While such systems are capable of achieving efficient processing of light sensitive web material in continuous form or in sheet form they utilize external pumps or plumbing to circulate the processing fluid and/or do not uniformly distribute the processing fluid across the width of the web being processed.